substance and style
Accounting for Cognitive Bias in Legal Reasoning and Writing by Pamela Keller
I
n earlier columns, I wrote about some of the science supporting legal writing advice. I cited empirical evidence and cognitive science principles backing up some well-known legal writing principles.1 This column discusses cognitive science that explains biases that all people have that can affect how we reason. Because these biases affect how we reason, you should understand them as you seek to persuade. After explaining what these cognitive biases are, I offer a few tips on how you should adjust the style and content of your legal writing to account for them in your advocacy. A cognitive bias can be described as a natural tendency our brains have when we process and interpret information. Much research has shown that our brains routinely use intellectual shortcuts in our everyday lives to simulate the results of logical reasoning, saving time and reducing cognitive load.2 But these shortcuts or rule-of-thumb approaches come with a price: They lead to systematic errors in judgment.3 These brain shortcuts don’t cause so many errors that we abandon them, but they create tendencies or biases in our thinking processes. When these biases creep into our legal reasoning, they prevent us from reaching better-reasoned decisions.4 Two natural tendencies or biases that can affect our legal reasoning are the confirmation bias and the bias blind spot. The confirmation bias is our brain’s tendency to want to confirm beliefs that we already hold. People tend to seek and more readily accept information they believe supports a hypothesis or an existing belief they have.5 They tend to interpret new information in ways that are more consistent with those already formed hypotheses or beliefs. And if information conflicts with a formed hypothesis or belief, or if it supports a 26
The Journal of the Kansas Bar Association
different hypothesis or conflicting belief, people tend to discount or even avoid that information.6 People also tend to pay more attention to evidence that shows their belief is correct,7 and they tend to pay less attention to or miss evidence that can prove their hypotheses are wrong.8 This bias can occur even when we form a hypothesis or belief on fairly thin evidence; and our beliefs tend to persevere even when the initial evidence on which they were based has been discredited.9 This natural tendency can affect legal reasoning. For example, once you decide to advocate for your client, your brain’s confirmation bias may filter evidence in your case in favor of your client. Your brain will have a tendency to accept information consistent with your client’s case and to discount the other side’s evidence and arguments. You are more likely to miss or pay less attention to conflicting evidence. Confirmation bias may also make it harder to change a decision-maker’s existing hypothesis or belief. If, for example, you are before a judge who simply does not like your case from the beginning, you may have to overcome the judge’s confirmation bias.10 This doesn’t mean the judge has made up her mind, but she may be more inclined to view the evidence in the other side’s favor.11 On the other hand, if you sense that your client’s story resonates with your judge from the outset, you may have an advantage you don’t want to lose. You need to control for confirmation bias in evaluating your case and adjust your advocacy as well. If your brain is telling you that you already adjust for this bias (after all, you learned to be objective and see the other side’s arguments in your first year of law school!), then you